RESUMO
Electrical devices, which have become an integral part of our daily life, may influence the electrical recording of the heart. These disturbances from external sources outside of the heart's own activity produce changes in the electrocardiography (ECG) of the patient, simulating rhythmic disturbances of the heart. Understanding these disturbances is essential in order to better interprete the ECG. Common sources of electrical interferences include external devices, such as alternating current and improper earthing, and surgical procedures like diathermy. We report a case of electrical interference in a patient's ECG due to an inserted bladder stimulator. This case report highlights the importance of precise identification of artefacts in the interpretation of ECG, as well as prompt localisation and elimination of the source of interference.